Class: Reddy::ConjunctiveGraph

Inherits:
Graph
  • Object
show all
Defined in:
lib/reddy/conjunctive_graph.rb

Overview

ConjunctiveGraph - The top level container for all named Graphs sharing a Store

A ConjuctiveGraph is a graph that can contain other graphs. Graphs are kept distinct by a context, which is the identifier of the sub-graph. It is the union of all graphs in a Store.

For the sake of persistence, Conjunctive Graphs must be distinguished by identifiers (that may not necessarily be RDF identifiers or may be an RDF identifier normalized - SHA1/MD5 perhaps - for database naming purposes ) which could be referenced to indicate conjunctive queries (queries made across the entire conjunctive graph) or appear as nodes in asserted statements. In this latter case, such statements could be interpreted as being made about the entire ‘known’ universe.

Instance Attribute Summary

Attributes inherited from Graph

#identifier, #nsbinding, #store, #triples

Instance Method Summary collapse

Methods inherited from Graph

#<<, #[], #add, #add_triple, #bind, #bnodes, #close, #commit, #contains?, #context_aware?, #destroy, #eql?, #get_by_type, #has_bnode_identifier?, #inspect, #merge!, #namespace, #objects, #open, #predicates, #prefix, #remove, #rollback, #size, #subjects, #to_ntriples, #to_rdfxml, #to_s

Constructor Details

#initialize(options = {}) ⇒ ConjunctiveGraph

Store for ConjunctiveGraph must support contexts.



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# File 'lib/reddy/conjunctive_graph.rb', line 16

def initialize(options = {})
  unless options[:store] && options[:store].context_aware?
    raise GraphException.new("Conjuective Graph requires store supporting contexts")
  end

  super(:identifier => options[:store].identifier, :store => options[:store])
  @context_aware = true
end

Instance Method Details

#default_context ⇒ Object

The default_context is a Graph having an identifier the same as the identifier of the store.



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# File 'lib/reddy/conjunctive_graph.rb', line 27

def default_context
  @@default_context = Graph.new(:identifier => @store.identifier, :store => @store)
end

#parse(stream, uri, options = {}, &block) ⇒ Graph

Parse source into a new context.

Create a new context (Graph) and parse into that.

options[:debug]

Array to place debug messages

options[:type]

One of rdfxml, html, or n3

options[:strict]

Raise Error if true, continue with lax parsing, otherwise

Parameters:

  • stream:: (IO, String) —

    the RDF IO stream, string, Nokogiri::HTML::Document or Nokogiri::XML::Document

  • uri:: (String) —

    the URI of the document

  • options:: (Hash) —

    Options from

Returns:

  • (Graph) —

    Returns the graph containing parsed triples



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# File 'lib/reddy/conjunctive_graph.rb', line 42

def parse(stream, uri, options = {}, &block) # :yields: triple
  graph = Graph.new(:identifier => uri, :store => self.store)
  Parser.parse(stream, uri, options.merge(:graph => graph), &block)
end